The present invention relates to an electrical connector for a cardiac pacemaker for connecting an electrode lead to a terminal on the pacemaker.
Implantable pacemakers suitable for sensing and/or pacing cardiac functions are well known in the art. Such devices operate in conjunction with electrode leads which have a distal end that is implanted in the tissue that is to be sensed or paced, and a proximal end that is connected to the pacemaker. Specifically, the proximal end is typically coupled to a terminal provided on the pacemaker so that electrical connection may be made between the electrode lead and circuitry within the pacemaker.
A number of concerns arise regarding the coupling between the pacemaker terminal and the electrode lead. In addition to desiring electrical connection between the two structures, it is important to ensure secure mechanical connection so that the lead does not become dislodged or disconnected from the terminal. Other concerns relate to providing a connector arrangement which is convenient to use so that the physician performing implantation of the pacemaker does not have difficulties in successfully connecting the electrode lead to the pacemaker terminal.
Various arrangements for connecting the electrode lead to the pacemaker terminal have been proposed and used in the art. U.S. Pat. No. 4,540,236 to Peers-Trevarton has a comprehensive review of the different types of lead electrode to pacemaker terminal connections that have been used, and deals not only with electrical connection but also mechanical connection and sealing arrangements. Another Peers-Trevarton patent, U.S. Pat. No. 4,469,104, discloses a connector assembly incorporated into the electrodes of a multi-conductor lead which utilizes resiliant conductive rings.
Other known connection methods utilize a grub screw provided perpendicularly to the electrode lead in order to secure the lead in place in a pacemaker terminal. An example of such an arrangement is disclosed in U.S. Pat. No. 4,445,511 to Cowdery et al.
Many of these different connection arrangements do not fully satisfy the various concerns outlined above, however. Some of the arrangements are complicated to manufacture or are inconvenient to use. Others require more space than is available in modern pacemakers, particularly pacers having relatively thin dimensions. Accordingly, a need still exists for a connection arrangement that is responsive to the various concerns associated with impantation or explantation of pacemakers.